Sabot projectile

ABSTRACT

A sabot projectile having pivotal vanes secured to support means, the vanes in a first position forming a substantially pyramid-shaped sabot and after pivoting about an axis into a second position forming a resistance-free guide mechanism. The tip of the pyramid-shaped sabot, viewed in the direction of flight, being directed towards the rear, and the lateral boundary surfaces of the vanes in a first position tightly bearing against one another under the action of the gas pressure, and the vanes being constructed as a T-guide or control mechanism and the vane pivot axes being directed perpendicular to the axis of the projectile.

United States Patent Mayer Nov. 5, 1974 SABOT PROJECTILE Primar Examiner-Ben' min A. Borchelt 75 l t l M F ll Y J l 1 men or ggz g r ayer a anden Assistant Examiner-C. T. Jordan Attorney, Agent, or Firm-Wcrner W. Klccman [73] Assignee: Werkzeugmaschinenfabrik Oerlikon-Buhrle AG, Zurich,

Switzerland ABSTRACT [22] Fil d; M 7, 1973 A sabot projectile having pivotal vanes secured to sup- Appl. No.: 358,141

port means, the vanes in a first position forming a substantially pyramid-shaped sabot and after pivoting about an axis into a second position forming a resist ance-free guide mechanism. The tip of the pyramidshaped sabot, viewed in the direction of flight, being directed towards the rear, and the lateral boundary surfaces of the vanes in a first position tightly bearing against one another under the action of the gas pressure, and the vanes being constructed as a T-guide or control mechanism and the vane pivot axes being directed perpendicular to the axis of the projectile.

7 Claims, 5 Drawing Figures SABOT PROJECTILE BACKGROUND OF THE INVENTION The present invention relates to a new and improved construction of sabot projectile of the type having vanes pivotably secured to supports, the vanes in a first position forming a substantially pyramid-shaped sabot and after rocking or pivoting about an axis into a second position forming a resistance-free guide or control mechanism. 2

Similar sabot projectiles are known to the art in different constructional manifestations. Their vanes are flat or planar and form in a first position a pyramid having a tip directed towards the front, and which serves as the sabot, the propellant gas being located internally of the pyramid. By means of the gas pressure the rear boundary surfaces of the sabot pyramid are pressed against the inner jacket of the firing barrel or bore, so that upon ejection of the projectile from the firing barrel high frictional forces must be overcome. The vanes are then pivoted into a second position about pivot axes which are directed obliquely with respect to the projectile axis, and in which position they form a knife guide or control mechanism which is less effective-than a T- guide mechanism.

SUMMARY OF THE INVENTION It is a primary object of the present invention to provide a sabot projectile which overcomes the aforementioned drawbacks of the prior art proposals.

Another and more specific object of the present invention aims at providing an improved construction of sabot projectile, the pivotal vanes of which, in a first position. form a relatively frictionless sabot and, in a second position, an effective guide or control mechamsm.

Now in order to implement these and still further objects of the invention, which will become more readily apparent as the description proceeds, the sabot projectile of this development is manifested by the features that the tip of the substantially pyramid-shaped sabot, viewed in the direction of flight, is directed towards the rear, that the lateral boundary surfaces of the vanes in their first position are tightly pressed into contact against one another under the action of the gas pressure, that the vanes are formed as a T-guide mechanism and the pivot axes of the vanes are directed perpendicular to the projectile axis.

BRIEF DESCRIPTION OF THE DRAWING The invention will be better understood and objects other than those set forth above, will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawing wherein:

FIG. 1 is a perspective view of a projectile located in a firing barrel, partially in section, and constituting a first exemplary embodiment of the invention;

FIG. 2 is a perspective view of the projectile depicted in FIG. 1 after leaving the firing barrel;

FIG. 3 is a view from the rear of the projectile depicted in FIG. 2;

FIG. 4 is a view of a second exemplary embodiment of the invention, similar to the showing of FIG. 3; and

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Describing now the drawing, and according to the exemplary embodiment of sabot projectile depicted in FIG. 1, there will be recognized that a'projectile, for instance a trench mortar projectile 2 is located in a firing barrel or bore 1, and the largest diameter of such projectile 2 is smaller than the diameter of the firing barrel 1. At the projectile 2 there are secured at the region of the center of gravity of the projectile three pivotable guide cams or dogs 3. The diameter of the projectile 2 is greatest at the central portion of such projectile and then reduces towards the rear thereof, as shown. -At

the rear end of the projectile 2 there'is secured a tail pipe 4. This tail pipe 4 is provided with four projections 5 of semi-circular cross-sectional configuration, and these four projections 5 are uniformly distributed about the periphery of the tail pipe 4. Further, each projection 5 is provided with a respective groove 7 arranged parallel to the projectile axis 6.

Now, at each projection 5 there is mounted a pivot shaft or pivot axis 8 which extendsperpendicular to the projectile axis 6 and to the associated groove 7. A parallelogram-shaped support or carrier 9 possesses a projection 11 at one of its corners 10, the thickness of this projection 11 being equal to the width of the groove 7, and also having a semi-circular crosssectional configuration of the same dimensions as the projections 5. The projection '11 at the support or carrier 9 engages into the groove 7 of projection 5 at the tail pipe 4 and is hingedly connected wtih the pivot shaft 8. The spacing of the pivot shaft 8 from the projectile axis 6 is equal to the radius of the tail-pipe 4. A planar or flat vane 12 is fixedly connected with the lengthwise extending side 13 of the support or carrier 9 opposite the projection 11 and is disposed perpendicular thereto. The symmetry axis of a vane encloses with the projectile axis 6 an angle a which is of the same magnitude as the acute angle of the parallelogramshaped support 9. The lateral boundary surfaces '14 of a vane 12 are located in two radial planes which are perpendicular to one another. The shape of the front boundary surface 15 of a vane 12, in the position depicted in FIG. 1, is governed by the requirement that the vane tightly contact or bears against the inner jacket of the firing barrel 1, the shape of the rear boundary surface 16 of a vane in the same position corresponds to the tail pipe 4. The front and rear boundary surfaces 15 and 16 of the vane are therefore elliptical. At the part of the tail pipe located behind the projections 5 there are pushed-on propellant charge bodies 17 which constitute the projectile propellant charge.

The mode of operation of the projectile discussed above will now be considered and is as follows:

According to the showing of FIG. 1, the front boundary surfaceslS of the vane 12 of the projectile 2 located in the firing barrel 1 bear against the inner wall of such firing barrel 1. Neighboring vanes 12 contact one another by means of their lateral boundary surfaces 14. The vane support 9 bears by means of its lateral boundary surface 18 at the base of the grooves. The four vanes 12 collectively form a pyramid having a tip directed towards the rear, and which serves as the sabot. The vanes 12 which snugly bear by means of the boundary surfaces 14 and against one another and against the firing barrel 1 close the charge compartment located behind the sabot towards the front. The projectile 2 is centered in the firing barrel 1 by means of the guide cams 3. Upon ingition of the propellant charge the projectile 2 is fired out of the firing barrel 1 under the action of the pressure of the propellant charge gases which act upon the sabot.

The gas pressure acts from the outside upon the vane pyramid and presses the side surfaces against one another, so that they completely tightly bear against one another. At the same time the front boundary surfaces 15 are slightly displaced away from the firing barrel 1, so that the friction between the sabot and the firing barrel is reduced.

After the projectile 2 has departed from the firing barrel 1 the guide cams 3 are rocked into the interior of the projectile. Since the pressure of the propellant charge gases no longer acts from the rear upon the vanes 12, the latter are rocked towards the rear by means of the forwardly inflowing air about the pivot axes or shafts 8. After pivoting through an angle of 180 a and according to the showing of FIGS. 2 and 3, the boundary surfaces 19 of the vane support 9 bear against the tail pipe 4 which has now been freed of the propellant charge 17. The vanes 12 and their supports 9 are located in planes which are parallel to the projectile axis 6. The supports 9 form a knife guide or control mechanism which is surrounded by a vane guide mechanism consisting of the vanes 12, resulting in a T-guide or control mechanism. j Theaif res tfitce induc ed by the guide or control mechanism is small. The forces generated by the propellant action act upon the vanes 12 in a direction perpendicular to the projectile axis. The length of the lever arm related to the center of gravity of the projectile, and at which there impinge such forces, is directly proportional to the cosine of the angle of attack of the pro jectile 2, in other words. is practically constant for the normally occurring angles of attack.

The spacing which the vanes 12 possess from the projectile axis 6 in the second position influences the effectiveness of the guide or control mechanism. This spacing can be influenced by the length of the edge 18 of vane carrier 9. According to FIG. 1, the vane spacing amounts to, for instance, the radius of the firing barrel 1.

Owing to the arrangement of the propellant charge behind the guide or control mechanism of the projectile 2, such can be simply changed by removlng from or pushing partial charges 17 onto the tail pipe 4. Instead of employing flat vanes it would also be possible to arrange such which consist of cylindrical surfaces. In their first position these vanes form sabots which are considerably more stable than sabots formed by planar or flat vanes. In their second position they form just as is the case for the planar vanes a resistance free guide mechanism, since they are secured in such a manner to the vane supports 9 that in their second position there is only flow impinged their end surfaces.

The exemplary embodiment in F [05. 4 and 5 possess vanes which consist of segments of thin-walled pipes or conduits. In one instance, as shown in the embodiment of FIG. 4, the vanes 20 are secured to the supports 9 in such a way that the axes of the cylinder, from which the vanes are formed, and which in the second position are parallel to the projectile axis, are located between the vanes and the projectile axis. In the other case, as shown in the embodiment of FIG. 5, the axes of the cylinders are located externally of the vane surfaces 21.

In the illustrated embodiments of the projectiles, all of which have four vanes, one is of course only concerned with illustrative exemplary embodiments. There could be equally provided a projectile having a different number of vanes.

While there is shown and described present preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto, but may be otherwise variously embodied and practiced within the scope of the following claims.

What is claimed is:

l. A sabot projectile comprisinga propellant charge provided for the sabot projectile for producing a gas pressure, support means, vanes pivotably secured to said support means, said vanes in a first position forming a substantially pyramid-shaped sabot and after pivoting about an axis into a second position forming a substantially resistance-free guide mechanism, the pyramid-shaped sabot having a tip which, viewed in the direction of flight of the sabot, is directed towards the rear, said vanes having lateral boundary surfaces which in the first position of said vanes tightly bear against one another under the action of the gas pressure of the propellant charge, said vanes being constructed as a T guide mechanism and the pivot axes of the vanes being directed perpendicular to the axis of the projectile.

2. A sabot projectile for use with a firing barrel having an inner jacket, comprising a projectile, a tail pipe supported by said projectile, support means fixed to said tail pipe, vanes pivotably secured to said support means, said vanes in a first position forming a substantially pyramid-shaped sabot having a tip which. viewed in the direction of flight of the sabot, is directed towards the rear, said vanes after pivoting about an axis into a second position forming a substantially resistance-free guide mechanism, said pyramid-shaped sabot having a greater diameter than the diameter of said projectile, said vanes having lateral boundary surfaces which in the first position of said vanes tightly bear against one another and against the inner jacket of the firing barrel, said tail pipe having a part thereof located behind said support means, said tail pipe part carrying propellant charge bodies constituting a projectile prolpellant charge for producing a gas pressure in the firing arrel.

3. The sabot projectile as defined in claim 2, wherein said vanes are substantially planar and upon assuming their second position form together with the support means a T-guide mechanism.

4. The sabot projectile as defined in claim 2, wherein said vanes are sections of cylindrical surfaces and said vanes, upon assuming their second position, form together with the support means a T-guide mechanism.

5. The sabot projectile as defined in claim 4, wherein the axis of the cylindrical surface defined by each vane and the projectile axis are located at the same side of the vanes.

6. The sabot projectile as defined in claim 4, wherein the axis of the cylindrical surface formed by each vane and the projectile axis is located at opposite sides of the vanes.

7. The sabot projectile as defined in claim 2, wherein the diameter of the projectile reduces towards the rear 

1. A sabot projectile comprising a propellant charge provided for the sabot projectile for producing a gas pressure, support means, vanes pivotably secured to said suppOrt means, said vanes in a first position forming a substantially pyramid-shaped sabot and after pivoting about an axis into a second position forming a substantially resistance-free guide mechanism, the pyramid-shaped sabot having a tip which, viewed in the direction of flight of the sabot, is directed towards the rear, said vanes having lateral boundary surfaces which in the first position of said vanes tightly bear against one another under the action of the gas pressure of the propellant charge, said vanes being constructed as a T-guide mechanism and the pivot axes of the vanes being directed perpendicular to the axis of the projectile.
 2. A sabot projectile for use with a firing barrel having an inner jacket, comprising a projectile, a tail pipe supported by said projectile, support means fixed to said tail pipe, vanes pivotably secured to said support means, said vanes in a first position forming a substantially pyramid-shaped sabot having a tip which, viewed in the direction of flight of the sabot, is directed towards the rear, said vanes after pivoting about an axis into a second position forming a substantially resistance-free guide mechanism, said pyramid-shaped sabot having a greater diameter than the diameter of said projectile, said vanes having lateral boundary surfaces which in the first position of said vanes tightly bear against one another and against the inner jacket of the firing barrel, said tail pipe having a part thereof located behind said support means, said tail pipe part carrying propellant charge bodies constituting a projectile propellant charge for producing a gas pressure in the firing barrel.
 3. The sabot projectile as defined in claim 2, wherein said vanes are substantially planar and upon assuming their second position form together with the support means a T-guide mechanism.
 4. The sabot projectile as defined in claim 2, wherein said vanes are sections of cylindrical surfaces and said vanes, upon assuming their second position, form together with the support means a T-guide mechanism.
 5. The sabot projectile as defined in claim 4, wherein the axis of the cylindrical surface defined by each vane and the projectile axis are located at the same side of the vanes.
 6. The sabot projectile as defined in claim 4, wherein the axis of the cylindrical surface formed by each vane and the projectile axis is located at opposite sides of the vanes.
 7. The sabot projectile as defined in claim 2, wherein the diameter of the projectile reduces towards the rear thereof. 